Interference mitigation in wireless communications

ABSTRACT

Certain aspects of the present disclosure provide techniques for interference mitigation. Certain aspects provide a method for wireless communication. The method generally includes performing communications, in a first channel, on a first downlink in a first time period based on communications in a second channel adjacent to the first channel being performed on a second downlink in the first time period. Communications in the first channel on a first uplink are performed in a second time period based on communication in the second channel being performed on a second uplink in the second time period. The method further includes refraining from communicating in the first channel on one or more resources in the first time period or the second time period to mitigate cross-link interference with a third channel adjacent to the first channel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent No.62/577,622, filed Oct. 26, 2017. The content of the provisionalapplication is hereby incorporated by reference in its entirety.

INTRODUCTION

Aspects of the present disclosure relate to wireless communications, andmore particularly, to techniques for interference mitigation.

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,broadcasts, etc. These wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power, etc.). Examples of such multiple-access systems include3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE)systems, LTE Advanced (LTE-A) systems, code division multiple access(CDMA) systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, orthogonal frequency divisionmultiple access (OFDMA) systems, single-carrier frequency divisionmultiple access (SC-FDMA) systems, and time division synchronous codedivision multiple access (TD-SCDMA) systems, to name a few.

In some examples, a wireless multiple-access communication system mayinclude a number of base stations (BSs), which are each capable ofsimultaneously supporting communication for multiple communicationdevices, otherwise known as user equipments (UEs). In an LTE or LTE-Anetwork, a set of one or more base stations may define an eNodeB (eNB).In other examples (e.g., in a next generation, a new radio (NR), or 5Gnetwork), a wireless multiple access communication system may include anumber of distributed units (DUs) (e.g., edge units (EUs), edge nodes(ENs), radio heads (RHs), smart radio heads (SRHs), transmissionreception points (TRPs), etc.) in communication with a number of centralunits (CUs) (e.g., central nodes (CNs), access node controllers (ANCs),etc.), where a set of one or more distributed units, in communicationwith a central unit, may define an access node (e.g., which may bereferred to as a base station, 5G NB, next generation NodeB (gNB orgNodeB), TRP, etc.). A base station or distributed unit may communicatewith a set of UEs on downlink channels (e.g., for transmissions from abase station or to a UE) and uplink channels (e.g., for transmissionsfrom a UE to a base station or distributed unit).

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. New Radio (NR) (e.g., 5G) is an exampleof an emerging telecommunication standard. NR is a set of enhancementsto the LTE mobile standard promulgated by 3GPP. It is designed to bettersupport mobile broadband Internet access by improving spectralefficiency, lowering costs, improving services, making use of newspectrum, and better integrating with other open standards using OFDMAwith a cyclic prefix (CP) on the downlink (DL) and on the uplink (UL).To these ends, NR supports beamforming, multiple-input multiple-output(MIMO) antenna technology, and carrier aggregation.

However, as the demand for mobile broadband access continues toincrease, there exists a need for further improvements in NR and LTEtechnology. Preferably, these improvements should be applicable to othermulti-access technologies and the telecommunication standards thatemploy these technologies.

BRIEF SUMMARY

The systems, methods, and devices of the disclosure each have severalaspects, no single one of which is solely responsible for its desirableattributes. Without limiting the scope of this disclosure as expressedby the claims which follow, some features will now be discussed briefly.After considering this discussion, and particularly after reading thesection entitled “Detailed Description” one will understand how thefeatures of this disclosure provide advantages that include improvedcommunications between access points and stations in a wireless network.

Certain aspects provide a method for wireless communication. The methodgenerally includes performing communications, in a first channel, on afirst downlink in a first time period based on communications in asecond channel adjacent to the first channel being performed on a seconddownlink in the first time period. Communications in the first channelon a first uplink are performed in a second time period based oncommunication in the second channel being performed on a second uplinkin the second time period. The method further includes refraining fromcommunicating in the first channel on one or more resources in the firsttime period or the second time period to mitigate cross-linkinterference with a third channel adjacent to the first channel.

Certain aspects provide a method for wireless communication. The methodgenerally includes performing communications in a first channel, whereinthe first channel is adjacent to a guard band, wherein the guard band isadjacent to a second channel used for LTE communication, wherein thefirst channel is further adjacent to a third channel used for NRcommunication, wherein communications in the first channel is restrictedto mitigate cross-link interference between the first channel and thesecond channel, wherein restricting communications in the first channelcomprises one or more of limiting a bandwidth of the first channel,using a sharp transmit filter, using a sharp receive filter, limitingtransmit power, or limiting antenna height.

Certain aspects provide a wireless communication device. The wirelesscommunication device includes a memory and a processor. The processor isconfigured to perform communications, in a first channel, on a firstdownlink in a first time period based on communications in a secondchannel adjacent to the first channel being performed on a seconddownlink in the first time period, wherein communications in the firstchannel on a first uplink are performed in a second time period based oncommunication in the second channel being performed on a second uplinkin the second time period. The processor is further configured torefrain from communicating in the first channel on one or more resourcesin the first time period or the second time period to mitigatecross-link interference with a third channel adjacent to the firstchannel.

Certain aspects provide a wireless communication device. The wirelesscommunication device includes means for performing communications, in afirst channel, on a first downlink in a first time period based oncommunications in a second channel adjacent to the first channel beingperformed on a second downlink in the first time period, whereincommunications in the first channel on a first uplink are performed in asecond time period based on communication in the second channel beingperformed on a second uplink in the second time period. The wirelesscommunication device further includes means for refraining fromcommunicating in the first channel on one or more resources in the firsttime period or the second time period to mitigate cross-linkinterference with a third channel adjacent to the first channel.

Certain aspects provide a non-transitory computer readable storagemedium that stores instructions that when executed by a base stationcause the base station to perform a method for wireless communication.The method generally includes performing communications, in a firstchannel, on a first downlink in a first time period based oncommunications in a second channel adjacent to the first channel beingperformed on a second downlink in the first time period. Communicationsin the first channel on a first uplink are performed in a second timeperiod based on communication in the second channel being performed on asecond uplink in the second time period. The method further includesrefraining from communicating in the first channel on one or moreresources in the first time period or the second time period to mitigatecross-link interference with a third channel adjacent to the firstchannel.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe appended drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description,briefly summarized above, may be had by reference to aspects, some ofwhich are illustrated in the drawings. It is to be noted, however, thatthe appended drawings illustrate only certain typical aspects of thisdisclosure and are therefore not to be considered limiting of its scope,for the description may admit to other equally effective aspects.

FIG. 1 is a block diagram conceptually illustrating an exampletelecommunications system, in accordance with certain aspects of thepresent disclosure.

FIG. 2 is a block diagram illustrating an example logical architectureof a distributed radio access network (RAN), in accordance with certainaspects of the present disclosure.

FIG. 3 is a diagram illustrating an example physical architecture of adistributed RAN, in accordance with certain aspects of the presentdisclosure.

FIG. 4 is a block diagram conceptually illustrating a design of anexample base station (BS) and user equipment (UE), in accordance withcertain aspects of the present disclosure.

FIG. 5 is a diagram showing examples for implementing a communicationprotocol stack, in accordance with certain aspects of the presentdisclosure.

FIG. 6 illustrates an example of a frame format for a new radio (NR)system, in accordance with certain aspects of the present disclosure.

FIGS. 7A and 7B are diagrams illustrating cross-link interference thatmay occur in a telecommunication system, in accordance with certainaspects of the present disclosure.

FIG. 8 illustrates adjacent channels of a frequency band for separatedeployments, in accordance with certain aspects of the presentdisclosure.

FIG. 9 illustrates communication timelines for separate deployments, inaccordance with aspects of the present disclosure.

FIG. 10 illustrates adjacent channels of a frequency band for separatedeployments, in accordance with aspects of the present disclosure.

FIG. 11 illustrates example operations that may be performed by awireless device for interference mitigation in accordance with aspectsof the present disclosure.

FIG. 12 illustrates example operations that may be performed by awireless device for interference mitigation in accordance with aspectsof the present disclosure.

FIG. 13 illustrates a communications device that may include variouscomponents configured to perform operations for the techniques disclosedherein, in accordance with aspects of the present disclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in one aspectmay be beneficially utilized on other aspects without specificrecitation.

DETAILED DESCRIPTION

Aspects of the present disclosure present disclosure provide apparatus,methods, processing systems, and computer readable mediums forinterference mitigation, such as cross-link interference mitigationbetween radio access technologies (RATs) (e.g., NR and LTE).

The following description provides examples, and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the scope of the disclosure. Various examples may omit,substitute, or add various procedures or components as appropriate. Forinstance, the methods described may be performed in an order differentfrom that described, and various steps may be added, omitted, orcombined. Also, features described with respect to some examples may becombined in some other examples. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition to,or other than, the various aspects of the disclosure set forth herein.It should be understood that any aspect of the disclosure disclosedherein may be embodied by one or more elements of a claim. The word“exemplary” is used herein to mean “serving as an example, instance, orillustration.” Any aspect described herein as “exemplary” is notnecessarily to be construed as preferred or advantageous over otheraspects.

The techniques described herein may be used for various wirelesscommunication technologies, such as LTE, CDMA, TDMA, FDMA, OFDMA,SC-FDMA and other networks. The terms “network” and “system” are oftenused interchangeably. A CDMA network may implement a radio technologysuch as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRAincludes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000covers IS-2000, IS-95 and IS-856 standards. A TDMA network may implementa radio technology such as Global System for Mobile Communications(GSM). An OFDMA network may implement a radio technology such as NR(e.g. 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRAand E-UTRA are part of Universal Mobile Telecommunication System (UMTS).

New Radio (NR) is an emerging wireless communications technology underdevelopment in conjunction with the 5G Technology Forum (5GTF). 3GPPLong Term Evolution (LTE) and LTE-Advanced (LTE-A) are releases of UMTSthat use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described indocuments from an organization named “3rd Generation PartnershipProject” (3GPP). cdma2000 and UMB are described in documents from anorganization named “3rd Generation Partnership Project 2” (3GPP2). Thetechniques described herein may be used for the wireless networks andradio technologies mentioned above as well as other wireless networksand radio technologies. For clarity, while aspects may be describedherein using terminology commonly associated with 3G and/or 4G wirelesstechnologies, aspects of the present disclosure can be applied in othergeneration-based communication systems, such as 5G and later, includingNR technologies.

New radio (NR) access (e.g., 5G technology) may support various wirelesscommunication services, such as enhanced mobile broadband (eMBB)targeting wide bandwidth (e.g., 80 MHz or beyond), millimeter wave (mmW)targeting high carrier frequency (e.g., 25 GHz or beyond), massivemachine type communications MTC (mMTC) targeting non-backward compatibleMTC techniques, and/or mission critical targeting ultra-reliablelow-latency communications (URLLC). These services may include latencyand reliability requirements. These services may also have differenttransmission time intervals (TTI) to meet respective quality of service(QoS) requirements. In addition, these services may co-exist in the samesubframe.

Example Wireless Communications System

FIG. 1 illustrates an example wireless communication network 100 inwhich aspects of the present disclosure may be performed. For example,the wireless communication network 100 may be a New Radio (NR) or 5Gnetwork. For example, BSs 110 and UEs 120 may perform cross-linkinterference mitigation between RATs as discussed herein.

As illustrated in FIG. 1, the wireless network 100 may include a numberof base stations (BSs) 110 and other network entities. A BS may be astation that communicates with user equipments (UEs). Each BS 110 mayprovide communication coverage for a particular geographic area. In3GPP, the term “cell” can refer to a coverage area of a Node B (NB)and/or a Node B subsystem serving this coverage area, depending on thecontext in which the term is used. In NR systems, the term “cell” andnext generation NodeB (gNB), new radio base station (NR BS), 5G NB,access point (AP), or transmission reception point (TRP) may beinterchangeable. In some examples, a cell may not necessarily bestationary, and the geographic area of the cell may move according tothe location of a mobile BS. In some examples, the base stations may beinterconnected to one another and/or to one or more other base stationsor network nodes (not shown) in wireless communication network 100through various types of backhaul interfaces, such as a direct physicalconnection, a wireless connection, a virtual network, or the like usingany suitable transport network.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular radioaccess technology (RAT) and may operate on one or more frequencies. ARAT may also be referred to as a radio technology, an air interface,etc. A frequency may also be referred to as a carrier, a subcarrier, afrequency channel, a tone, a subband, etc. Each frequency may support asingle RAT in a given geographic area in order to avoid interferencebetween wireless networks of different RATs. In some cases, NR or 5G RATnetworks may be deployed.

A base station (BS) may provide communication coverage for a macro cell,a pico cell, a femto cell, and/or other types of cells. A macro cell maycover a relatively large geographic area (e.g., several kilometers inradius) and may allow unrestricted access by UEs with servicesubscription. A pico cell may cover a relatively small geographic areaand may allow unrestricted access by UEs with service subscription. Afemto cell may cover a relatively small geographic area (e.g., a home)and may allow restricted access by UEs having an association with thefemto cell (e.g., UEs in a Closed Subscriber Group (CSG), UEs for usersin the home, etc.). A BS for a macro cell may be referred to as a macroBS. A BS for a pico cell may be referred to as a pico BS. A BS for afemto cell may be referred to as a femto BS or a home BS. In the exampleshown in FIG. 1, the BSs 110 a, 110 b and 110 c may be macro BSs for themacro cells 102 a, 102 b and 102 c, respectively. The BS 110 x may be apico BS for a pico cell 102 x. The BSs 110 y and 110 z may be femto BSsfor the femto cells 102 y and 102 z, respectively. A BS may support oneor multiple (e.g., three) cells.

Wireless communication network 100 may also include relay stations. Arelay station is a station that receives a transmission of data and/orother information from an upstream station (e.g., a BS or a UE) andsends a transmission of the data and/or other information to adownstream station (e.g., a UE or a BS). A relay station may also be aUE that relays transmissions for other UEs. In the example shown in FIG.1, a relay station 110 r may communicate with the BS 110 a and a UE 120r in order to facilitate communication between the BS 110 a and the UE120 r. A relay station may also be referred to as a relay BS, a relay,etc.

Wireless network 100 may be a heterogeneous network that includes BSs ofdifferent types, e.g., macro BS, pico BS, femto BS, relays, etc. Thesedifferent types of BSs may have different transmit power levels,different coverage areas, and different impact on interference in thewireless network 100. For example, macro BS may have a high transmitpower level (e.g., 20 Watts) whereas pico BS, femto BS, and relays mayhave a lower transmit power level (e.g., 1 Watt).

Wireless communication network 100 may support synchronous orasynchronous operation. For synchronous operation, the BSs may havesimilar frame timing, and transmissions from different BSs may beapproximately aligned in time. For asynchronous operation, the BSs mayhave different frame timing, and transmissions from different BSs maynot be aligned in time. The techniques described herein may be used forboth synchronous and asynchronous operation.

A network controller 130 may couple to a set of BSs and providecoordination and control for these BSs. The network controller 130 maycommunicate with the BSs 110 via a backhaul. The BSs 110 may alsocommunicate with one another (e.g., directly or indirectly) via wirelessor wireline backhaul.

The UEs 120 (e.g., 120 x, 120 y, etc.) may be dispersed throughout thewireless network 100, and each UE may be stationary or mobile. A UE mayalso be referred to as a mobile station, a terminal, an access terminal,a subscriber unit, a station, a Customer Premises Equipment (CPE), acellular phone, a smart phone, a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, alaptop computer, a cordless phone, a wireless local loop (WLL) station,a tablet computer, a camera, a gaming device, a netbook, a smartbook, anultrabook, an appliance, a medical device or medical equipment, abiometric sensor/device, a wearable device such as a smart watch, smartclothing, smart glasses, a smart wrist band, smart jewelry (e.g., asmart ring, a smart bracelet, etc.), an entertainment device (e.g., amusic device, a video device, a satellite radio, etc.), a vehicularcomponent or sensor, a smart meter/sensor, industrial manufacturingequipment, a global positioning system device, or any other suitabledevice that is configured to communicate via a wireless or wired medium.Some UEs may be considered machine-type communication (MTC) devices orevolved MTC (eMTC) devices. MTC and eMTC UEs include, for example,robots, drones, remote devices, sensors, meters, monitors, locationtags, etc., that may communicate with a BS, another device (e.g., remotedevice), or some other entity. A wireless node may provide, for example,connectivity for or to a network (e.g., a wide area network such asInternet or a cellular network) via a wired or wireless communicationlink. Some UEs may be considered Internet-of-Things (IoT) devices, whichmay be narrowband IoT (NB-IoT) devices.

Certain wireless networks (e.g., LTE) utilize orthogonal frequencydivision multiplexing (OFDM) on the downlink and single-carrierfrequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDMpartition the system bandwidth into multiple (K) orthogonal subcarriers,which are also commonly referred to as tones, bins, etc. Each subcarriermay be modulated with data. In general, modulation symbols are sent inthe frequency domain with OFDM and in the time domain with SC-FDM. Thespacing between adjacent subcarriers may be fixed, and the total numberof subcarriers (K) may be dependent on the system bandwidth. Forexample, the spacing of the subcarriers may be 15 kHz and the minimumresource allocation (called a “resource block” (RB)) may be 12subcarriers (or 180 kHz). Consequently, the nominal Fast FourierTransfer (FFT) size may be equal to 128, 256, 512, 1024 or 2048 forsystem bandwidth of 1.25, 2.5, 5, 10, or 20 megahertz (MHz),respectively. The system bandwidth may also be partitioned intosubbands. For example, a subband may cover 1.08 MHz (i.e., 6 resourceblocks), and there may be 1, 2, 4, 8, or 16 subbands for systembandwidth of 1.25, 2.5, 5, 10 or 20 MHz, respectively.

While aspects of the examples described herein may be associated withLTE technologies, aspects of the present disclosure may be applicablewith other wireless communications systems, such as NR. NR may utilizeOFDM with a CP on the uplink and downlink and include support forhalf-duplex operation using TDD. Beamforming may be supported and beamdirection may be dynamically configured. MIMO transmissions withprecoding may also be supported. MIMO configurations in the DL maysupport up to 8 transmit antennas with multi-layer DL transmissions upto 8 streams and up to 2 streams per UE. Multi-layer transmissions withup to 2 streams per UE may be supported. Aggregation of multiple cellsmay be supported with up to 8 serving cells.

In some examples, access to the air interface may be scheduled, whereina. A scheduling entity (e.g., a base station) allocates resources forcommunication among some or all devices and equipment within its servicearea or cell. The scheduling entity may be responsible for scheduling,assigning, reconfiguring, and releasing resources for one or moresubordinate entities. That is, for scheduled communication, subordinateentities utilize resources allocated by the scheduling entity. Basestations are not the only entities that may function as a schedulingentity. In some examples, a UE may function as a scheduling entity andmay schedule resources for one or more subordinate entities (e.g., oneor more other UEs), and the other UEs may utilize the resourcesscheduled by the UE for wireless communication. In some examples, a UEmay function as a scheduling entity in a peer-to-peer (P2P) network,and/or in a mesh network. In a mesh network example, UEs may communicatedirectly with one another in addition to communicating with a schedulingentity.

In FIG. 1, a solid line with double arrows indicates desiredtransmissions between a UE and a serving BS, which is a BS designated toserve the UE on the downlink and/or uplink. A finely dashed line withdouble arrows indicates interfering transmissions between a UE and a BS.

FIG. 2 illustrates an example logical architecture of a distributedRadio Access Network (RAN) 200, which may be implemented in the wirelesscommunication network 100 illustrated in FIG. 1. A 5G access node 206may include an access node controller (ANC) 202. ANC 202 may be acentral unit (CU) of the distributed RAN 200. The backhaul interface tothe Next Generation Core Network (NG-CN) 204 may terminate at ANC 202.The backhaul interface to neighboring next generation access Nodes(NG-ANs) 210 may terminate at ANC 202. ANC 202 may include one or moretransmission reception points (TRPs) 208 (e.g., cells, BSs, gNBs, etc.).

The TRPs 208 may be a distributed unit (DU). TRPs 208 may be connectedto a single ANC (e.g., ANC 202) or more than one ANC (not illustrated).For example, for RAN sharing, radio as a service (RaaS), and servicespecific AND deployments, TRPs 208 may be connected to more than oneANC. TRPs 208 may each include one or more antenna ports. TRPs 208 maybe configured to individually (e.g., dynamic selection) or jointly(e.g., joint transmission) serve traffic to a UE.

The logical architecture of distributed RAN 200 may support fronthaulingsolutions across different deployment types. For example, the logicalarchitecture may be based on transmit network capabilities (e.g.,bandwidth, latency, and/or jitter).

The logical architecture of distributed RAN 200 may share featuresand/or components with LTE. For example, next generation access node(NG-AN) 210 may support dual connectivity with NR and may share a commonfronthaul for LTE and NR.

The logical architecture of distributed RAN 200 may enable cooperationbetween and among TRPs 208, for example, within a TRP and/or across TRPsvia ANC 202. An inter-TRP interface may not be used.

Logical functions may be dynamically distributed in the logicalarchitecture of distributed RAN 200. As will be described in more detailwith reference to FIG. 5, the Radio Resource Control (RRC) layer, PacketData Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer,Medium Access Control (MAC) layer, and a Physical (PHY) layers may beadaptably placed at the DU (e.g., TRP 208) or CU (e.g., ANC 202).

FIG. 3 illustrates an example physical architecture of a distributedRadio Access Network (RAN) 300, according to aspects of the presentdisclosure. A centralized core network unit (C-CU) 302 may host corenetwork functions. C-CU 302 may be centrally deployed. C-CU 302functionality may be offloaded (e.g., to advanced wireless services(AWS)), in an effort to handle peak capacity.

A centralized RAN unit (C-RU) 304 may host one or more ANC functions.Optionally, the C-RU 304 may host core network functions locally. TheC-RU 304 may have distributed deployment. The C-RU 304 may be close tothe network edge.

A DU 306 may host one or more TRPs (Edge Node (EN), an Edge Unit (EU), aRadio Head (RH), a Smart Radio Head (SRH), or the like). The DU may belocated at edges of the network with radio frequency (RF) functionality.

FIG. 4 illustrates example components of BS 110 and UE 120 (as depictedin FIG. 1), which may be used to implement aspects of the presentdisclosure. For example, antennas 452, processors 466, 458, 464, and/orcontroller/processor 480 of the UE 120 and/or antennas 434, processors420, 460, 438, and/or controller/processor 440 of the BS 110 may be usedto perform the various techniques and methods described herein.

At the BS 110, a transmit processor 420 may receive data from a datasource 412 and control information from a controller/processor 440. Thecontrol information may be for the physical broadcast channel (PBCH),physical control format indicator channel (PCFICH), physical hybrid ARQindicator channel (PHICH), physical downlink control channel (PDCCH),group common PDCCH (GC PDCCH), etc. The data may be for the physicaldownlink shared channel (PDSCH), etc. The processor 420 may process(e.g., encode and symbol map) the data and control information to obtaindata symbols and control symbols, respectively. The processor 420 mayalso generate reference symbols, e.g., for the primary synchronizationsignal (PSS), secondary synchronization signal (SSS), and cell-specificreference signal (CRS). A transmit (TX) multiple-input multiple-output(MIMO) processor 430 may perform spatial processing (e.g., precoding) onthe data symbols, the control symbols, and/or the reference symbols, ifapplicable, and may provide output symbol streams to the modulators(MODs) 432 a through 432 t. Each modulator 432 may process a respectiveoutput symbol stream (e.g., for OFDM, etc.) to obtain an output samplestream. Each modulator may further process (e.g., convert to analog,amplify, filter, and upconvert) the output sample stream to obtain adownlink signal. Downlink signals from modulators 432 a through 432 tmay be transmitted via the antennas 434 a through 434 t, respectively.

At the UE 120, the antennas 452 a through 452 r may receive the downlinksignals from the base station 110 and may provide received signals tothe demodulators (DEMODs) in transceivers 454 a through 454 r,respectively. Each demodulator 454 may condition (e.g., filter, amplify,downconvert, and digitize) a respective received signal to obtain inputsamples. Each demodulator may further process the input samples (e.g.,for OFDM, etc.) to obtain received symbols. A MIMO detector 456 mayobtain received symbols from all the demodulators 454 a through 454 r,perform MIMO detection on the received symbols if applicable, andprovide detected symbols. A receive processor 458 may process (e.g.,demodulate, deinterleave, and decode) the detected symbols, providedecoded data for the UE 120 to a data sink 460, and provide decodedcontrol information to a controller/processor 480.

On the uplink, at UE 120, a transmit processor 464 may receive andprocess data (e.g., for the physical uplink shared channel (PUSCH)) froma data source 462 and control information (e.g., for the physical uplinkcontrol channel (PUCCH) from the controller/processor 480. The transmitprocessor 464 may also generate reference symbols for a reference signal(e.g., for the sounding reference signal (SRS)). The symbols from thetransmit processor 464 may be precoded by a TX MIMO processor 466 ifapplicable, further processed by the demodulators in transceivers 454 athrough 454 r (e.g., for SC-FDM, etc.), and transmitted to the basestation 110. At the BS 110, the uplink signals from the UE 120 may bereceived by the antennas 434, processed by the modulators 432, detectedby a MIMO detector 436 if applicable, and further processed by a receiveprocessor 438 to obtain decoded data and control information sent by theUE 120. The receive processor 438 may provide the decoded data to a datasink 439 and the decoded control information to the controller/processor440.

The controllers/processors 440 and 480 may direct the operation at thebase station 110 and the UE 120, respectively. The processor 440 and/orother processors and modules at the BS 110 may perform or direct theexecution of processes for the techniques described herein. The memories442 and 482 may store data and program codes for BS 110 and UE 120,respectively. A scheduler 444 may schedule UEs for data transmission onthe downlink and/or uplink.

FIG. 5 illustrates a diagram 500 showing examples for implementing acommunications protocol stack, according to aspects of the presentdisclosure. The illustrated communications protocol stacks may beimplemented by devices operating in a wireless communication system,such as a 5G system (e.g., a system that supports uplink-basedmobility). Diagram 500 illustrates a communications protocol stackincluding a Radio Resource Control (RRC) layer 510, a Packet DataConvergence Protocol (PDCP) layer 515, a Radio Link Control (RLC) layer520, a Medium Access Control (MAC) layer 525, and a Physical (PHY) layer530. In various examples, the layers of a protocol stack may beimplemented as separate modules of software, portions of a processor orASIC, portions of non-collocated devices connected by a communicationslink, or various combinations thereof. Collocated and non-collocatedimplementations may be used, for example, in a protocol stack for anetwork access device (e.g., ANs, CUs, and/or DUs) or a UE.

A first option 505-a shows a split implementation of a protocol stack,in which implementation of the protocol stack is split between acentralized network access device (e.g., an ANC 202 in FIG. 2) anddistributed network access device (e.g., DU 208 in FIG. 2). In the firstoption 505-a, an RRC layer 510 and a PDCP layer 515 may be implementedby the central unit, and an RLC layer 520, a MAC layer 525, and a PHYlayer 530 may be implemented by the DU. In various examples the CU andthe DU may be collocated or non-collocated. The first option 505-a maybe useful in a macro cell, micro cell, or pico cell deployment.

A second option 505-b shows a unified implementation of a protocolstack, in which the protocol stack is implemented in a single networkaccess device. In the second option, RRC layer 510, PDCP layer 515, RLClayer 520, MAC layer 525, and PHY layer 530 may each be implemented bythe AN. The second option 505-b may be useful in, for example, a femtocell deployment.

Regardless of whether a network access device implements part or all ofa protocol stack, a UE may implement an entire protocol stack as shownin 505-c (e.g., the RRC layer 510, the PDCP layer 515, the RLC layer520, the MAC layer 525, and the PHY layer 530).

In LTE, the basic transmission time interval (TTI) or packet duration isthe 1 ms subframe. In NR, a subframe is still 1 ms, but the basic TTI isreferred to as a slot. A subframe contains a variable number of slots(e.g., 1, 2, 4, 8, 16, . . . slots) depending on the subcarrier spacing.The NR RB is 12 consecutive frequency subcarriers. NR may support a basesubcarrier spacing of 15 KHz and other subcarrier spacing may be definedwith respect to the base subcarrier spacing, for example, 30 kHz, 60kHz, 120 kHz, 240 kHz, etc. The symbol and slot lengths scale with thesubcarrier spacing. The CP length also depends on the subcarrierspacing.

FIG. 6 is a diagram showing an example of a frame format 600 for NR. Thetransmission timeline for each of the downlink and uplink may bepartitioned into units of radio frames. Each radio frame may have apredetermined duration (e.g., 10 ms) and may be partitioned into 10subframes, each of 1 ms, with indices of 0 through 9. Each subframe mayinclude a variable number of slots depending on the subcarrier spacing.Each slot may include a variable number of symbol periods (e.g., 7 or 14symbols) depending on the subcarrier spacing. The symbol periods in eachslot may be assigned indices. A mini-slot, which may be referred to as asub-slot structure, refers to a transmit time interval having a durationless than a slot (e.g., 2, 3, or 4 symbols).

Each symbol in a slot may indicate a link direction (e.g., DL, UL, orflexible) for data transmission and the link direction for each subframemay be dynamically switched. The link directions may be based on theslot format. Each slot may include DL/UL data as well as DL/UL controlinformation.

In NR, a synchronization signal (SS) block is transmitted. The SS blockincludes a PSS, a SSS, and a two symbol PBCH. The SS block can betransmitted in a fixed slot location, such as the symbols 2-5 as shownin FIG. 6. The PSS and SSS may be used by UEs for cell search andacquisition. The PSS may provide half-frame timing, the SS may providethe CP length and frame timing. The PSS and SSS may provide the cellidentity. The PBCH carries some basic system information, such asdownlink system bandwidth, timing information within radio frame, SSburst set periodicity, system frame number, etc. The SS blocks may beorganized into SS bursts to support beam sweeping. Further systeminformation such as, remaining minimum system information (RMSI), systeminformation blocks (SIBs), other system information (OSI) can betransmitted on a physical downlink shared channel (PDSCH) in certainsubframes.

In some circumstances, two or more subordinate entities (e.g., UEs) maycommunicate with each other using sidelink signals. Real-worldapplications of such sidelink communications may include public safety,proximity services, UE-to-network relaying, vehicle-to-vehicle (V2V)communications, Internet of Everything (IoE) communications, IoTcommunications, mission-critical mesh, and/or various other suitableapplications. Generally, a sidelink signal may refer to a signalcommunicated from one subordinate entity (e.g., UE1) to anothersubordinate entity (e.g., UE2) without relaying that communicationthrough the scheduling entity (e.g., UE or BS), even though thescheduling entity may be utilized for scheduling and/or controlpurposes. In some examples, the sidelink signals may be communicatedusing a licensed spectrum (unlike wireless local area networks, whichtypically use an unlicensed spectrum).

A UE may operate in various radio resource configurations, including aconfiguration associated with transmitting pilots using a dedicated setof resources (e.g., a radio resource control (RRC) dedicated state,etc.) or a configuration associated with transmitting pilots using acommon set of resources (e.g., an RRC common state, etc.). Whenoperating in the RRC dedicated state, the UE may select a dedicated setof resources for transmitting a pilot signal to a network. Whenoperating in the RRC common state, the UE may select a common set ofresources for transmitting a pilot signal to the network. In eithercase, a pilot signal transmitted by the UE may be received by one ormore network access devices, such as an AN, or a DU, or portionsthereof. Each receiving network access device may be configured toreceive and measure pilot signals transmitted on the common set ofresources, and also receive and measure pilot signals transmitted ondedicated sets of resources allocated to the UEs for which the networkaccess device is a member of a monitoring set of network access devicesfor the UE. One or more of the receiving network access devices, or a CUto which receiving network access device(s) transmit the measurements ofthe pilot signals, may use the measurements to identify serving cellsfor the UEs, or to initiate a change of serving cell for one or more ofthe UEs.

Example Interference Mitigation

FIGS. 7A and 7B are diagrams illustrating cross-link interference thatmay occur in a telecommunication system.

FIGS. 7A and 7B show a first BS 710 a (e.g., a BS 110 as shown anddescribed in FIG. 1) with a coverage area shown by cell 702 a and asecond BS 710 b with a coverage area shown by cell 702 b. FIGS. 7A and7B further show a first UE 720 a (e.g., a UE 120 as shown and describedin FIG. 1) connected to first BS 710 a and a second UE 720 b connectedto second BS 710 b. In certain aspects, BS 710 a may utilize a first RAT(e.g., NR or LTE) for communication with UE 720 a, and BS 710 b mayutilize a second RAT (e.g., the other of LTE or NR) or communicationwith UE 720 b.

In certain aspects, as illustrated in FIG. 7A, UL transmissions from UE720 b to BS 710 b may interfere with DL transmissions from BS 710 a toUE 720 a at UE 720 a. For example, the UL transmissions in cell 702 bmay be on the same or adjacent channel(s) (e.g., frequency range(s)) ofa frequency band as the DL transmissions in cell 702 a. For example, BS710 b and 710 a may be part of separate TDD deployments (e.g., separatenetworks such as operated by the same or different network operators)that share the same or adjacent channel(s) for DL and UL transmissions.Accordingly, the UL transmissions from UE 720 b may be received at UE720 a and interfere with the DL transmissions from BS 110 a received atUE 720 a. Such cross-link interference between UL and DL transmissionsmay cause problems and poor performance.

In certain aspects, as illustrated in FIG. 7B, DL transmissions from BS710 a to UE 720 a may interfere with UL transmissions from UE 720 b toBS 710 b at BS 710 b. In particular, the DL transmissions from BS 710 amay be received at BS 710 b and interfere with the UL transmissions fromUE 720 b received at BS 710 b. Such cross-link interference between ULand DL transmissions may cause problems and poor performance. Thescenario in FIG. 7B may be more prevalent or problematic, in some cases,than the scenario in FIG. 7A since interference between BSs may be morelikely to happen due to their fixed location and potential placement athigh heights giving them line of sight between the BSs. Therefore, thestrength of the transmissions from BS 710 a at BS 710 b may be high,making the interference with UL transmissions from UE 720 b worse.Interference may not only occur in the same channel, but also acrossadjacent channels.

In certain aspects, to overcome such cross-link interference between ULand DL transmissions, the transmission direction (e.g., UL and DL) maybe aligned between adjacent deployments (e.g., adjacent BSs 710 a and710 b), meaning that both BSs 710 a and 710 b schedule UL transmissionsat the same time and DL transmissions at the same time, so DLtransmissions cannot interfere with UL transmissions. Accordingly, largeguard bands are not needed between channels used for DL and UL, meaningthe spectrum resources are utilized efficiently. However, thedeployments of BS 710 a and 710 b may then be restricted from usingdifferent UL/DL configuration timings, which may impact performance as astrict configuration must always be adhered to.

In certain aspects, to overcome such cross-link interference between ULand DL transmissions, a guard band may be used between adjacent channelsused for UL and DL, thereby reducing/eliminating interference betweenthe adjacent channels even if transmissions occur at the same time. Thisallows for more flexible deployments of BSs, but leads tounderutilization of spectrum as the guard band corresponds to portionsof the frequency band not used for transmissions.

Accordingly, certain aspects herein relate to other techniques forovercoming cross-link interference that use a small or no guard band,but still allow flexible deployments.

FIG. 8 illustrates adjacent channels of a frequency band for separatedeployments. For example, frequency band 800 is divided into a firstchannel 802, a second channel 804, and a third channel 806. The firstchannel 802 may be used for a first deployment (e.g., of a firstnetwork), the second channel 804 for a second deployment, and the thirdchannel 806 for a third deployment. The first channel 802 may be for afirst RAT (e.g., LTE), and the second and third channels 806 and 808 maybe for a second RAT (e.g., NR). In certain aspects, different or thesame RATs may be used for the channels.

In certain aspects, in order to mitigate cross-link interference betweenthe first deployment on first channel 802 and the second deployment onsecond channel 804, the second deployment could align its transmissiondirection with the first deployment. However, in order to mitigatecross-link interference between the second deployment on second channel804 and the third deployment on third channel 806, the third deploymentwould then need to align its transmission direction with the seconddeployment. Further deployments on adjacent channels would also need toalign transmission direction, which would limit flexibility in eachdeployment.

Accordingly, in certain aspects, the second deployment on second channel804 may align its transmission direction with the first channel 802, butmay also blank out certain resources (i.e., not utilize certainresources for communication on the second channel 804) (e.g., resourcesthat would conflict with the direction of the DL and/or UL controlblocks containing control information for NR self-contained subframestructure). Therefore, the third deployment on third channel 806 can usethe blanked out resources (e.g., for communication of DL and/or ULcontrol information). Therefore, the second deployment may have somerestricted communication configuration, but does not interfere with thefirst deployment, and provides flexibility to the third deployment forscheduling UL and DL transmissions. This flexibility may also extend tosubsequent deployments in adjacent channels from channel 806 of thethird deployment. Further, where the first deployment is LTE and thesecond and third deployment are NR deployments, the LTE deployment isprotected from cross-link interference by the transmission directionalignment, while the third deployment and any other adjacent NRdeployments have flexibility in scheduling UL and DL transmissions. Inparticular, NR may be designed to better deal with cross-linkinterference than LTE in certain aspects. Though the deployments areshown on adjacent channels, in certain aspects, some may be on the samechannel.

FIG. 9 illustrates communication timelines for separate deployments. Asshown, a first deployment (e.g., communicating on channel 802) utilizesLTE TDD for communication as shown in timeline 902. In the firstdeployment, as shown in timeline 902, a first subframe 950 is used forDL communication, a second subframe 952 is used for shared UL/DLcommunication, a third subframe 954 is used for UL communication, afourth subframe 956 is used for DL communication, and a fifth subframe958 is used for DL communication. As shown, in second subframe 952, afirst set of resources (e.g., time resources) 910 is used for DLcommunication, a second set of resources 912 is not used forcommunication (are blanked), and a third set of resources 914 is usedfor UL communication.

A second deployment (e.g., communicating on channel 804) utilizes NR forcommunication as shown in timelines 904 and 904′. Timeline 904represents communications by the second deployment where it aligns itstransmissions with the first deployment, but does not blank outresources as discussed. In certain aspects, the slot length of thesecond deployment may be half that of the first deployment as shown(e.g., the second deployment is a 30 kHz deployment). As shown,resources 920 are used for communication of DL control information,resources 922 are used for DL data communication, resources 924 areblanked out or not utilized, resources 926 are used for communication ofUL control information, and resources 928 are used for UL datacommunication. As shown, the DL/UL transmissions in timeline 904 arecompletely aligned with timeline 902, so there is not cross-linkinterference.

Time line 904′ represents communications by the second deployment whereit aligns its transmissions with the first deployment and blanks outresources, according to aspects described herein. In particular, asshown, time line 904′ is similar to time line 904, except additionalresources 924 are blanked out. Such resources 924 are not used by thesecond deployment for transmissions. The blanking out of such resources924, as discussed, can be used to protect transmission of DL and/or ULcontrol blocks including control information by deployments (e.g., NRdeployments) operating in adjacent channel(s) to the second deployment.

Accordingly, the third deployment is free to utilize the blanked outresources 924 of the second deployment shown in time line 904′ for otherpurposes (e.g., UL control transmission, DL control transmission, ULdata transmission, and/or DL data transmission) providing schedulingflexibility in the third deployment. The third deployment (e.g.,communicating on channel 806) utilizes NR for communication as shown intimeline 906. For example, as shown in subframe 950 (and similarlysubframes 954-958), third deployment can utilize resources 926 for ULcontrol information and resources 928 for UL data, even though subframe950 is used for DL communication only in the first deployment and thesecond deployment. Further, since the second deployment and thirddeployment utilize NR, the third deployment may use resources 928 for ULdata communication that are used for DL data communication in the seconddeployment (e.g., as shown in subframe 950), or may use resources 922for DL data communication that are used for UL data communication in thethird deployment (e.g., as shown in subframe 954) due to bettercross-link interference mitigation in NR. However, the third deploymentmay only schedule communication of UL and/or DL control information thataligns with the same UL and/or DL control information as the seconddeployment, or that aligns with blanked out resources 924 of the seconddeployment as any additional interference in control informationtransmissions may lead to poor performance. Therefore, in certainaspects, the blanked out resources 924 on the second deployment are usedonly for UL control information transmission and/or DL controlinformation transmission, and not for UL data transmission and/or DLdata transmission.

In certain aspects, as discussed, a guard band may be utilized betweenfirst channel 802 and second channel 804 to prevent cross-linkinterference. Where the first deployment on channel 802 uses LTE, andthe second deployment on channel 804 uses NR, and deployments onadjacent channels (e.g., channel 806) to channel 804 also use NR, the NRtechniques for cross-link interference may be used between the channelsused for NR, while the channel used for LTE is still protected by theguard band. In certain aspects, in order to limit the size (e.g.,frequency range) of the guard band, a special sub-band may be used thatis adjacent to the guard band. The sub-band may have certainrestrictions that mitigate cross-link interference with the channel usedfor LTE.

For example, FIG. 10 illustrates adjacent channels of a frequency bandfor separate deployments. For example, frequency band 1000 is dividedinto first channel(s) 1002, a guard band 1003, a second channel 1004,and third channel(s) 1006. The first channels 1002 may be used fordeployment(s) for a first RAT (e.g., LTE). The second channel 1004 maybe used for deployment(s) for a second RAT (e.g., NR). The thirdchannels 1006 may be used for deployment(s) for the second RAT as well.

In certain aspects, the second channel 1004 may be used as a specialsub-band having restrictions that mitigate cross-link interference withthe first channel(s) 1002 used for LTE. For example, the second channel1004 may have a limited (e.g., smaller bandwidth). Since channel leakageof a waveform is proportional to the bandwidth of the waveform, thelower bandwidth transmissions on the second channel 1004 accordingly mayhave less leakage into adjacent channels. In certain aspects, thedeployment(s) on second channel 1004 may align its transmissiondirection with the first channel(s) 1002 and also blank out certainresources such as according to the techniques discussed herein tomitigate cross link interference. In certain aspects, the deployment(s)on second channel 1004 may one or more of use a smaller bandwidth NRchannel, use a sharper transmitter filter to reduce leakage to adjacentchannels, use a sharper receiver filter to better block leakage fromadjacent channels, use a lower transmit power for transmissions, or makesure BS antenna heights are lower so signal propagation is less causingless interference. In certain aspects, LTE deployments in the firstchannel 1002 adjacent to guard band 1003 may use similar restrictions.

FIG. 11 illustrates example operations that may be performed by awireless device (e.g., BS 110/710 or UE 110/720) for interferencemitigation in accordance with aspects of the present disclosure.

Operations 1100 begin, at 1102, by performing communications, in a firstchannel, on a first downlink in a first time period based oncommunications in a second channel adjacent to the first channel beingperformed on a second downlink in the first time period, whereincommunications in the first channel on a first uplink are performed in asecond period based on communication in the second channel beingperformed on a second uplink in the second time period. At 1104,operations 1100 continue by refraining from communicating in the firstchannel on one or more resources in the first time period or the secondtime period to mitigate cross-link interference with a third channeladjacent to the first channel.

FIG. 12 illustrates example operations that may be performed by awireless device (e.g., 110/710 or UE 120/720) for interferencemitigation in accordance with aspects of the present disclosure.

Operations 1200 begin, at 1202, by performing communications in a firstchannel, wherein the first channel is adjacent to a guard band, whereinthe guard band is adjacent to a second channel used for LTEcommunication, wherein the first channel is further adjacent to a thirdchannel used for NR communication, wherein communications in the firstchannel is restricted to mitigate cross-link interference between thefirst channel and the second channel, wherein restricting communicationsin the first channel comprises one or more of limiting a bandwidth ofthe first channel, using a sharp transmit filter, using a sharp receivefilter, limiting transmit power, or limiting antenna height.

FIG. 13 illustrates a communications device 1300 that may includevarious components (e.g., corresponding to means-plus-functioncomponents) configured to perform operations for the techniquesdisclosed herein, such as the operations illustrated in FIGS. 11 and/or12. The communications device 1300 includes a processing system 1314coupled to a transceiver 1312. The transceiver 1312 is configured totransmit and receive signals for the communications device 1300 via anantenna 1320, such as the various signal described herein. Theprocessing system 1314 may be configured to perform processing functionsfor the communications device 1300, including processing signalsreceived and/or to be transmitted by the communications device 1300.

The processing system 1314 includes a processor 1308 coupled to acomputer-readable medium/memory 1311 via a bus 1324. In certain aspects,the computer-readable medium/memory 1311 is configured to storeinstructions that when executed by processor 1308, cause the processor1308 to perform the operations illustrated in FIGS. 11 and/or 12, orother operations for performing the various techniques discussed herein.

In certain aspects, the processing system 1314 further includes a firstperforming component 1302 for performing the operations illustrated at1102 in FIG. 11. Additionally, the processing system 1314 includes arefraining component 1304 for performing the operations illustrated at1104 in FIG. 11. The processing system 1314 also includes a secondperforming component 1306 for performing the operations illustrated at1202 in FIG. 12. The first performing component 1302, refrainingcomponent 1304, and second performing component 1306 may be coupled tothe processor 1308 via bus 1324. In certain aspects, the firstperforming component 1302, refraining component 1304, and secondperforming component 1306 may be hardware circuits. In certain aspects,the first performing component 1302, refraining component 1304, andsecond performing component 1306 may be software components that areexecuted and run on processor 1308.

The methods disclosed herein comprise one or more steps or actions forachieving the methods. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isspecified, the order and/or use of specific steps and/or actions may bemodified without departing from the scope of the claims.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: a, b, or c” is intended to cover a, b, c,a-b, a-c, b-c, and a-b-c, as well as any combination with multiples ofthe same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b,b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

As used herein, the term “determining” encompasses a wide variety ofactions. For example, “determining” may include calculating, computing,processing, deriving, investigating, looking up (e.g., looking up in atable, a database or another data structure), ascertaining and the like.Also, “determining” may include receiving (e.g., receiving information),accessing (e.g., accessing data in a memory) and the like. Also,“determining” may include resolving, selecting, choosing, establishingand the like.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language of the claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. All structural andfunctional equivalents to the elements of the various aspects describedthroughout this disclosure that are known or later come to be known tothose of ordinary skill in the art are expressly incorporated herein byreference and are intended to be encompassed by the claims. Moreover,nothing disclosed herein is intended to be dedicated to the publicregardless of whether such disclosure is explicitly recited in theclaims. No claim element is to be construed under the provisions of 35U.S.C. § 112(f) unless the element is expressly recited using the phrase“means for” or, in the case of a method claim, the element is recitedusing the phrase “step for.”

The various operations of methods described above may be performed byany suitable means capable of performing the corresponding functions.The means may include various hardware and/or software component(s)and/or module(s), including, but not limited to a circuit, anapplication specific integrated circuit (ASIC), or processor. Generally,where there are operations illustrated in figures, those operations mayhave corresponding counterpart means-plus-function components withsimilar numbering.

The various illustrative logical blocks, modules and circuits describedin connection with the present disclosure may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device (PLD),discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any commercially available processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

If implemented in hardware, an example hardware configuration maycomprise a processing system in a wireless node. The processing systemmay be implemented with a bus architecture. The bus may include anynumber of interconnecting buses and bridges depending on the specificapplication of the processing system and the overall design constraints.The bus may link together various circuits including a processor,machine-readable media, and a bus interface. The bus interface may beused to connect a network adapter, among other things, to the processingsystem via the bus. The network adapter may be used to implement thesignal processing functions of the PHY layer. In the case of a userterminal 120 (see FIG. 1), a user interface (e.g., keypad, display,mouse, joystick, etc.) may also be connected to the bus. The bus mayalso link various other circuits such as timing sources, peripherals,voltage regulators, power management circuits, and the like, which arewell known in the art, and therefore, will not be described any further.The processor may be implemented with one or more general-purpose and/orspecial-purpose processors. Examples include microprocessors,microcontrollers, DSP processors, and other circuitry that can executesoftware. Those skilled in the art will recognize how best to implementthe described functionality for the processing system depending on theparticular application and the overall design constraints imposed on theoverall system.

If implemented in software, the functions may be stored or transmittedover as one or more instructions or code on a computer readable medium.Software shall be construed broadly to mean instructions, data, or anycombination thereof, whether referred to as software, firmware,middleware, microcode, hardware description language, or otherwise.Computer-readable media include both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. The processor may beresponsible for managing the bus and general processing, including theexecution of software modules stored on the machine-readable storagemedia. A computer-readable storage medium may be coupled to a processorsuch that the processor can read information from, and write informationto, the storage medium. In the alternative, the storage medium may beintegral to the processor. By way of example, the machine-readable mediamay include a transmission line, a carrier wave modulated by data,and/or a computer readable storage medium with instructions storedthereon separate from the wireless node, all of which may be accessed bythe processor through the bus interface. Alternatively, or in addition,the machine-readable media, or any portion thereof, may be integratedinto the processor, such as the case may be with cache and/or generalregister files. Examples of machine-readable storage media may include,by way of example, RAM (Random Access Memory), flash memory, ROM (ReadOnly Memory), PROM (Programmable Read-Only Memory), EPROM (ErasableProgrammable Read-Only Memory), EEPROM (Electrically ErasableProgrammable Read-Only Memory), registers, magnetic disks, opticaldisks, hard drives, or any other suitable storage medium, or anycombination thereof. The machine-readable media may be embodied in acomputer-program product.

A software module may comprise a single instruction, or manyinstructions, and may be distributed over several different codesegments, among different programs, and across multiple storage media.The computer-readable media may comprise a number of software modules.The software modules include instructions that, when executed by anapparatus such as a processor, cause the processing system to performvarious functions. The software modules may include a transmissionmodule and a receiving module. Each software module may reside in asingle storage device or be distributed across multiple storage devices.By way of example, a software module may be loaded into RAM from a harddrive when a triggering event occurs. During execution of the softwaremodule, the processor may load some of the instructions into cache toincrease access speed. One or more cache lines may then be loaded into ageneral register file for execution by the processor. When referring tothe functionality of a software module below, it will be understood thatsuch functionality is implemented by the processor when executinginstructions from that software module.

Also, any connection is properly termed a computer-readable medium. Forexample, if the software is transmitted from a website, server, or otherremote source using a coaxial cable, fiber optic cable, twisted pair,digital subscriber line (DSL), or wireless technologies such as infrared(IR), radio, and microwave, then the coaxial cable, fiber optic cable,twisted pair, DSL, or wireless technologies such as infrared, radio, andmicrowave are included in the definition of medium. Disk and disc, asused herein, include compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk, and Blu-ray® disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Thus, in some aspects computer-readable media maycomprise non-transitory computer-readable media (e.g., tangible media).In addition, for other aspects computer-readable media may comprisetransitory computer-readable media (e.g., a signal). Combinations of theabove should also be included within the scope of computer-readablemedia.

Thus, certain aspects may comprise a computer program product forperforming the operations presented herein. For example, such a computerprogram product may comprise a computer-readable medium havinginstructions stored (and/or encoded) thereon, the instructions beingexecutable by one or more processors to perform the operations describedherein. For example, instructions for performing the operationsdescribed herein and illustrated in FIGS. 11 and 12.

Further, it should be appreciated that modules and/or other appropriatemeans for performing the methods and techniques described herein can bedownloaded and/or otherwise obtained by a user terminal and/or basestation as applicable. For example, such a device can be coupled to aserver to facilitate the transfer of means for performing the methodsdescribed herein. Alternatively, various methods described herein can beprovided via storage means (e.g., RAM, ROM, a physical storage mediumsuch as a compact disc (CD) or floppy disk, etc.), such that a userterminal and/or base station can obtain the various methods uponcoupling or providing the storage means to the device. Moreover, anyother suitable technique for providing the methods and techniquesdescribed herein to a device can be utilized.

It is to be understood that the claims are not limited to the preciseconfiguration and components illustrated above. Various modifications,changes and variations may be made in the arrangement, operation anddetails of the methods and apparatus described above without departingfrom the scope of the claims.

What is claimed is:
 1. A method for wireless communication, the methodcomprising: performing downlink communications, in a first channel, in afirst time period and a third time period after the first time periodthat is adjacent in time to the first time period based on downlinkcommunications in a second channel adjacent to the first channel beingperformed in the first time period and the third time period, whereinuplink communications in the first channel are performed in a secondtime period based on uplink communication in the second channel beingperformed in the second time period; and refraining from communicatingin the first channel on one or more resources in the first time periodto mitigate cross-link interference with a third channel adjacent to thefirst channel, the one or more resources in the first time periodoccurring in time after at least one resource in the first channel usedfor downlink communications in the first channel during the first timeperiod.
 2. The method of claim 1, wherein uplink communications in thethird channel are performed during the one or more resources in thefirst time period.
 3. The method of claim 2, wherein the uplinkcommunications comprise uplink control information communication.
 4. Themethod of claim 1, further comprising refraining from communicating inone or more resources in the second time period to mitigate cross-linkinterference with the third channel.
 5. The method of claim 4, whereindownlink communications in the third channel are performed during theone or more resources in the second time period.
 6. The method of claim5, wherein the downlink communications comprise downlink controlinformation communication.
 7. The method of claim 1, wherein there is aguard band adjacent to the first channel and between the first channeland the second channel, wherein the second channel is used for LTEcommunication, wherein the first channel is used for NR communication,wherein communications in the first channel is restricted to mitigatecross-link interference between the first channel and the secondchannel, wherein restricting communications in the first channelcomprises one or more of limiting a bandwidth of the first channel,using a sharp transmit filter, using a sharp receive filter, limitingtransmit power, or limiting antenna height.
 8. The method of claim 7,wherein communications in the second channel are also restricted.
 9. Awireless communication device, comprising: a memory; and a processorconfigured to: perform downlink communications, in a first channel, in afirst time period and a third time period after the first time periodthat is adjacent in time to the first time period based on downlinkcommunications in a second channel adjacent to the first channel beingperformed in the first time period and the third time period, whereinunlink communications in the first channel are performed in a secondtime period based on uplink communication in the second channel beingperformed in the second time period; and refrain from communicating inthe first channel on one or more resources in the first time period tomitigate cross-link interference with a third channel adjacent to thefirst channel, the one or more resources in the first time periodoccurring in time after at least one resource in the first channel usedfor downlink communications in the first channel during the first timeperiod.
 10. The wireless communication device of claim 9, wherein uplinkcommunications in the third channel are performed during the one or moreresources in the first time period.
 11. The wireless communicationdevice of claim 10, wherein the uplink communications comprise uplinkcontrol information communication.
 12. The wireless communication deviceof claim 9, wherein the processor is further configured to refrain fromcommunicating in one or more resources in the second time period tomitigate cross-link interference with the third channel.
 13. Thewireless communication device of claim 12, wherein downlinkcommunications in the third channel are performed during the one or moreresources in the second time period.
 14. The wireless communicationdevice of claim 13, wherein the downlink communications comprisedownlink control information communication.
 15. The wirelesscommunication device of claim 9, wherein there is a guard band adjacentto the first channel and between the first channel and the secondchannel, wherein the second channel is used for LTE communication,wherein the first channel is used for NR communication, whereincommunications in the first channel is restricted to mitigate cross-linkinterference between the first channel and the second channel, whereinrestricting communications in the first channel comprises one or more oflimiting a bandwidth of the first channel, using a sharp transmitfilter, using a sharp receive filter, limiting transmit power, orlimiting antenna height.
 16. The wireless communication device of claim15, wherein communications in the second channel are also restricted.17. A wireless communication device, comprising: means for performingdownlink communications, in a first channel, in a first time period anda third time period after the first time period that is adjacent in timeto the first time period based on downlink communications in a secondchannel adjacent to the first channel being performed in the first timeperiod and the third time period, wherein uplink communications in thefirst channel are performed in a second time period based on uplinkcommunication in the second channel being performed in the second timeperiod; and means for refraining from communicating in the first channelon one or more resources in the first time period to mitigate cross-linkinterference with a third channel adjacent to the first channel, the oneor more resources in the first time period occurring in time after atleast one resource in the first channel used for downlink communicationsin the first channel during the first time period.
 18. The wirelesscommunication device of claim 17, wherein uplink communications in thethird channel are performed during the one or more resources in thefirst time period.
 19. The wireless communication device of claim 18,wherein the uplink communications comprise uplink control informationcommunication.
 20. The wireless communication device of claim 17,further comprising means for refraining from communicating in one ormore resources in the second time period to mitigate cross-linkinterference with the third channel.
 21. The wireless communicationdevice of claim 20, wherein downlink communications in the third channelare performed during the one or more resources in the second timeperiod.
 22. The wireless communication device of claim 21, wherein thedownlink communications comprise downlink control informationcommunication.
 23. The wireless communication device of claim 17,wherein there is a guard band adjacent to the first channel and betweenthe first channel and the second channel, wherein the second channel isused for LTE communication, wherein the first channel is used for NRcommunication, wherein communications in the first channel is restrictedto mitigate cross-link interference between the first channel and thesecond channel, wherein restricting communications in the first channelcomprises one or more of limiting a bandwidth of the first channel,using a sharp transmit filter, using a sharp receive filter, limitingtransmit power, or limiting antenna height.
 24. The wirelesscommunication device of claim 23, wherein communications in the secondchannel are also restricted.
 25. A non-transitory computer readablestorage medium that stores instructions that when executed by a basestation cause the base station to perform a method for wirelesscommunication, the method comprising: performing downlinkcommunications, in a first channel, in a first time period and a thirdtime period after the first time period that is adjacent in time to thefirst time period based on downlink communications in a second channeladjacent to the first channel being performed in the first time periodand the third time period, wherein uplink communications in the firstchannel are performed in a second time period based on uplinkcommunication in the second channel being performed in the second timeperiod; and refraining from communicating in the first channel on one ormore resources in the first time period to mitigate cross-linkinterference with a third channel adjacent to the first channel, the oneor more resources in the first time period occurring in time after atleast one resource in the first channel used for downlink communicationsin the first channel during the first time period.
 26. Thenon-transitory computer readable storage medium of claim 25, whereinuplink communications in the third channel are performed during the oneor more resources in the first time period.
 27. The non-transitorycomputer readable storage medium of claim 26, wherein the uplinkcommunications comprise uplink control information communication. 28.The non-transitory computer readable storage medium of claim 25, themethod further comprising refraining from communicating in one or moreresources in the second time period to mitigate cross-link interferencewith the third channel.
 29. The non-transitory computer readable storagemedium of claim 28, wherein downlink communications in the third channelare performed during the one or more resources in the second timeperiod.